--- On Fri, 22/5/09, Hugh Robinson wrote:
> I have two groups followed across different time
> periods. I would like to test for a difference in
> survival between groups.
> It is my understanding that sts test will not work
> because the survival curves are for different
> periods (observed and expected events are exact and
> therefore p=1.0).
As long as you used -stset- correctly the period
should not matter and you should just be able to use
-st test-. All that matters is the time till a certain
event, that the initial time is different for different
groups (this is how I read "the curves are for
different periods") is irrelevant, you just need to
make sure that Stata knows which starting time to use
for which observation (this is what I mean with "use
-stset- correctly").
Hope this helps,
Maarten
-- Maarten
-----------------------------------------
Maarten L. Buis
Institut fuer Soziologie
Universitaet Tuebingen
Wilhelmstrasse 36
72074 Tuebingen
Germany
http://home.fsw.vu.nl/m.buis/
-----------------------------------------
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